The International Alliance for NanoEHS Harmonization (IANH) organises interlaboratory comparisons of methods relevant for a better understanding of the biological impacts of nano-objects, to highlight and remove sources of irreproducibility in existing protocols. Here we show results of the first IANH studies. The test materials used (suspensions of Au, silica, polystyrene and ceria nanoparticles) were assessed for homogeneity, to ensure a minimal contribution to between-laboratory variability. Robust statistics were used in case of considerable within- and between-laboratory variability. It is shown that, if detailed shipping, test and reporting protocols are respected, measurement of the size of nanoparticles in monodisperse suspensions is reproducible, also for centrally prepared and globally shipped samples. This conclusion is not valid for measurements on more polydisperse suspensions of nanoparticles aggregates, for which ultrasonication was observed to even increase variability. Also, the variability of the measured zeta potential values indicates a need for better surface charge test protocols.
Citation: Nature Nanotechnology
Pub Type: Journals
nanomaterial, nanoparticle, dispersion, interlaboratory study, zeta potential, particle size, toxicology, health